USPSTF Draft Recommendation

Screen Vision in Children Ages 3-5; Evidence Lacking for Younger Kids

Research has shown that amblyopia or its risk factors -- strabismus, anisometropia, or both -- is present in 1 percent to 6 percent of preschool-age children. If this condition goes untreated during childhood, it can lead to permanent vision loss or impairment.

However, the USPSTF found that current evidence is insufficient to assess the balance of benefits and harms of vision screening in children younger than 3 -- an "I" recommendation.

"Identification of vision abnormalities in preschool-aged children allows the abnormality to be corrected while the brain is still developing, which can prevent permanent vision loss," said USPSTF member Alex Kemper, M.D., M.P.H., M.S., in a news release(www.uspreventiveservicestaskforce.org) that accompanied the announcement.

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The U.S. Preventive Services Task Force (USPSTF) posted a draft recommendation statement and draft evidence review on Feb. 28 that call for clinicians to conduct vision screening at least once in children ages 3-5 years.

However, the USPSTF found that current evidence is insufficient to assess the balance of benefits and harms of vision screening in children younger than age 3.

The task force found vision screening tools accurately detected visual abnormalities, including amblyopia, strabismus and refractive errors. Children who receive a positive result on a screening test should be referred for a full eye examination to confirm the presence of vision abnormalities and receive treatment.

Furthermore, the group noted, treating these eye disorders becomes less effective with age. On the extreme end of the spectrum, amblyopia regularly becomes irreversible if not treated by ages 6-10.

USPSTF members called for additional research to better understand the balance of benefits and harms of screening in children younger than age 3.

Jennifer Frost, M.D., medical director for the AAFP Health of the Public and Science Division, told AAFP News the Academy supported the USPSTF's final recommendation on this topic in 2011 with its own recommendation, and the task force's new draft recommendation is unchanged from that earlier statement and is consistent with what family physicians are already doing.

Screening Tests

Family physicians can use a variety of screening tests to identify visual abnormalities in children, including visual acuity tests to screen for visual deficits associated with amblyopia and refractive error and ocular alignment tests for strabismus.

According to the draft statement, stereoacuity testing "is often omitted and may be performed incorrectly when attempted in a primary care setting."

If testing is performed in a child younger than age 3, "screening can include vision assessment, including external inspection for gross abnormalities, fixation and follow test (visual acuity), red reflex test (media opacity) and pupil examination with a penlight," said the statement.

Additionally, the task force noted that the corneal light reflex test (for strabismus) can be performed at any age, including in preverbal children, and instrument-based vision screening (i.e., autorefractors and photoscreeners) may be used in very young children, including infants.

Other options for vision screening in children older than age 3 can include external inspection of the eyes, the red reflex test, the cover-uncover test (strabismus) and evaluation of visual acuity with charts.

USPSTF members did not find adequate evidence to determine the optimal screening interval in children ages 3-5.

Family Physician's Take

Frost said she performed external eye exams on all children in her practice, regardless of age. In addition, she routinely performed a visual acuity exam using a Snellen chart during the age 4-5 well-child checkup.

She said it's important to screen vision in children ages 3-5 because by this age, they are generally able to participate in a vision exam -- making it more accurate -- yet it's early enough to intervene if problems are detected.

"This is also when children are getting ready to start school, so it is an ideal time to discuss the importance of vision," Frost said.

As for vision screening in children younger than age 3, Frost said eye exams are still routinely done but visual acuity exams can prove more difficult.

"This is more challenging, and sometimes impossible, in younger children, resulting in more false-positive results," she said.